1. Field of the Invention
The invention relates in general to respirators and in particular to a new and useful respirator with means for the circulation of the respiratory air including a coiled high-pressure tube as pressure gas tank.
2. Description of the Prior Art
Respirators, including those with circulation of the respiratory air, are worn by the user always under especially unpleasant circumstances. They are to enable him to stay and to perform physical work in an unbreathable environmental atmosphere over a long period of time. The work to be performed is heavy. The passageways to be gone through, as for example in mining, are often narrow and low. The respirators must therefore be light weight, small, and convenient to carry.
A known circulation respirator having means for the regeneration of the respiratory air contains in a respirator housing, as a built-in element, an oxygen tank consisting of a high-pressure tube which is coiled transverse to its longitudinal axis in the manner of a volute spring, so that the form of a spiral among others, may result. It is further curved in the longitudinal axis, so that it hugs the back plate of the housing. In front of the oxygen tank a respiratory pouch is provided. The regeneration cartridge is located in the respirator housing above the oxygen tank. It is thus arranged in the housing directly opposite the wearer's back. Thereby the temperature drop occuring upon expansion of the oxygen is not utilized for cooling the regeneration cartridge, which may in use heat up to about 100.degree. C. The circulation respirator is worn with a strap device fastened to the housing, although this is not shown. While this device is flat, it is very long because of the arrangement of the regeneration cartridge above the oxygen tank. Very disadvantageous is the above-mentioned missing heat protection, and not even some other insulation is provided (German Pat. No. 615,890).
Another respirator has a compressed gas storage tank designed as a flat part. This involves an injector, with which the outside air a drawn in for respiration. The injector is operated with gas from the compressed gas storage tank.
The tank comprises either individual smaller pressure gas vessels which are connected together by connecting pipes, or two sheet metal plates welded together, both provided with inter-connected indentations which after the welding together form communicating compressed gas storage chambers. The sheet metal plates as well as the individual small pressure gas vessels may be adapted to the wearer's body form. The other controls, such as the injector, pressure reducer, etc., may be disposed in part on one and in part on the other side of the compressed gas storage tank. The tank, which is flat, may be designed as a carrying frame. The carrying straps may be attached to it directly. The first named design of the compressed gas storage tank is very expensive because of the connecting pipes. For the attachment of the carrying straps, a special carrying frame is necessary, The realization of the compressed gas storage tank from the welded plates is not feasible in a profitable quantity with respect to manufacturing technique, for if the high pressure is not to affect the individual cavities, the weld between them must be gas-tight, to withstand the relatively high pressure. The use of this compressed gas storage tank in a circulation respirator, that is, including those with a regeneration cartridge, is not solved, and no solution is visible from the arrangement (German Pat. No. 971,689).